From: kturing@... (kate turing)
Date: 2002-01-26T19:12:53+09:00
Subject: Re: "friend" alternative in Ruby?

Mike Sassak <msassak@speakeasy.org> wrote in message news:<1012006343.5969.3.camel@synecdoche>...
> Could you elaborate on how you want your program to work?

Thanks for the response. I am doing something very similar 
to your second example.

I'll try to flesh out my problem a little more without 
dragging the application's obscure domain into the problem. 
FooMgr is a factory and manager for Foo objects. I'm doing 
this sort of this:

fm = FooMgr.new
resources.each do |r|
  f = fm.createFoo(r)
end

# Assume there's a FooMgr.[] method that returns a foo.
# I want this to work.
fm[somekey].doPublicThing  

# I want this to not work.
fm[somekey].doPrivateThing 

# and i want this method to work
def FooMgr.frobulate 
   #@foos is a private
   @foos[somekey].doPrivateThing
end

Also, I'd like to enforce that Foo objects can only
be created by a FooMgr. The first possibility that
comes to mind is protecting Foo.initialize in the 
same way that I'd like to protect Foo.doPrivateThing.

Looking into #send was an interesting read. But it 
feels a little low-level. Well, a lot.

I don't think I can cleanly do exactly what I want in 
Ruby. Maybe I just need to get comfortable with leaving 
doPrivateThing public, as much as it pains me. BUT, I
suspect that someone out there (who is less tainted by 
C++) has a Ruby-friendly way of accomplishing the same 
thing. Hope they speak up.

k